1. Ecology: Species Interactions Ch. 8-2

2. Community Ecology  Just as populations contain interacting members of a single species, communities contain interacting populations of many species.  There are 5 major interactions between species:  Predation  Competition  Parasitism  Mutualism  Commensalism

3. Predation  An individual of one species, called a predator, eats all or part of an individual of another species, called the prey.  Predation is powerful in a community  Influences the size of each population and how each species lives  Examples of Predators:  Carnivores  Herbivores  (all heterotrophs are either predators, parasites, or both)

4. Predator Adaptations  What makes a good predator?  Natural selection favors the evolution of predator adaptations for finding, capturing, and consuming prey  Ex:  Rattlesnakes  Wolves  Spiders  Cheetah  Tigers

5. Adaptations in Animal Prey  What are some adaptations that organism’s use to avoid predation?  Natural Selection favors traits that allow prey to escape, avoid, or ward off predators  Some flee  Others escape by hiding or resembling other objects  Deceptive markings (false eyes or heads)  Chemical Defenses and bright colors

6. Prey Adaptations

7. Mimicry  Mimicry: this is a defense where a HARMLESS species mimics a dangerous or distaste full species  It does this so that its predators will think it is poisonous or distasteful. It is protected because it looks like someone else who is dangerous!

8. Can you guess which snake is the MIMIC?  "Red on yellow, kill a fellow. Red on black, won't hurt Jack."  Scarlet king snake on the left is the mimic, and the coral snake on the right is the venomous one

9. Adaptations in Plant Prey  Plants cannot run from predators so they have developed their own defenses.  Sharp thorns, spikes, sticky hairs, or tough leaves  Chemical defenses (secondary compounds)

10. Plant Defenses

12. COMPETITION  A Niche is an organism’s role in its environment (where it lives, what it eats, what resources it uses etc).  Competition happens when two organisms have overlapping niches or when resources are limited.  The competitive exclusion principle says “no two organisms can survive with the same exact niche”… one has to be eliminated by the competition.

13. Competition  If 2 species share the same niche, something has to happen:  One will get killed  Share (Resource Partitioning)  One species will be pushed out or leave  Evolve to be different (Character Displacement)

14. What are symbiotic relationships?  They occur when there are close, long- term interactions between two organisms!  Parasitism (+, -)  Mutualism- (+,+)  Commensalism (+,0)

15. PARASITISM (+,-)  One organism is harmed while the other benefits.  The __________ feeds on the _____________.  Usually parasitism does not result in the _____________________________ of the host. The parasite wants to keep the host alive to feed off of it. Parasite Host Immediate death

16. Parasites

17. A physician pulls a 19-foot tapeworm from a man who has been treated with deworming medication. The Worm Project helps to provide funds used for the manufacture of 5-cent pills that provide deworming treatment.

18. Mutualism (+,+)  Is cooperative…. where both species benefit!  Ex. Pollination, Cleaner Wrasse

19. COMMENSALISM (+, 0)  One benefits and the other is not affected.  Ex. Cattle egret birds eat the insects that are forced out of their hiding places when buffalo move through the grass.  (who benefits?_______________________  Who is not affected? _______________)

20. Commensalism: Remoras